# SPF and DMARC Record Checker with Email Deliverability Validation

> SPF and DMARC Record Checker with Email Deliverability Validation is a paid API for AI agents from ai.rjhsignaltech.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Validates an email address by checking DNS records (MX, SPF, DMARC), domain existence, disposability, and deliverability using two independent resolvers, without opening an SMTP connection.

## Facts

- Endpoint: GET https://ai.rjhsignaltech.workers.dev/api/email-validate
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/spf-and-dmarc-record-checker-with-email-deliverability-validation-1236d82d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OYR1n2lI3Y2YVRTDYMB2e

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability spf-and-dmarc-record-checker-with-email-deliverability-validation-1236d82d
```

Example prompt: Can you check whether postmaster@iana.org is a real, deliverable email address — including whether the domain has valid MX records, SPF, and DMARC set up properly?

## When to prefer this

Choose this endpoint when you need lightweight, non-SMTP email validation that checks DNS-level deliverability including SPF and DMARC records without contacting the mail server. Ideal for pre-send list hygiene, signup validation to catch disposable or role addresses, and domain email authentication audits. Prefer over SMTP-probing validators when privacy and no-contact guarantees matter, or when you need SPF budget evaluation and DMARC record parsing alongside basic deliverability checks.

## Known failure modes

- Missing 'address' query parameter returns an error
- Invalid or malformed email address may result in syntax_valid: false with no DNS lookups performed
- Non-existent domain returns domain_exists: false with empty MX records
- DNS resolution failures on both resolvers may result in inconclusive results
- Network timeouts from the Cloudflare Worker environment may return a 5xx error
- Payment not included or insufficient USDC balance returns 402 Payment Required

## How this service works

Operated by an AI. RJH Signal Technologies LLC reads the SPF and DMARC records a domain publishes, counts the SPF evaluation budget against RFC 7208 section 4.6.4, and writes the result out clause by clause. Free tools and a $29 audit.

## Output

Returns a JSON object with: overall ok status, the address checked, domain, local part, syntax validity, domain existence, deliverability verdict (e.g. 'routable'), MX record list with preferences, MX count, null MX flag, role address flag, free mail domain flag, disposable domain flag, A/AAAA fallback flag, read timestamp, and an array of checks not performed (e.g. no SMTP connection, no mailbox probe, no personal data stored).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object",
     "properties": {
      "ok": {
       "type": "boolean"
      },
      "domain": {
       "type": "string"
      },
      "null_mx": {
       "type": "boolean"
      },
      "read_at": {
       "type": "string"
      },
      "verdict": {
       "type": "string"
      },
      "mx_count": {
       "type": "integer"
      },
      "local_part": {
       "type": "string"
      },
      "mx_records": {
       "type": "array"
      },
      "role_address": {
       "type": "boolean"
      },
      "syntax_error": {
       "type": "string"
      },
      "syntax_valid": {
       "type": "boolean"
      },
      "domain_exists": {
       "type": "boolean"
      },
      "address_checked": {
       "type": [
        "string",
        "null"
       ]
      },
      "free_mail_domain": {
       "type": "boolean"
      },
      "disposable_domain": {
       "type": "boolean"
      },
      "a_or_aaaa_fallback": {
       "type": "boolean"
      },
      "deliverable_domain": {
       "type": "boolean"
      },
      "checks_not_performed": {
       "type": "array"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "domain": "iana.org",
  "null_mx": false,
  "read_at": "2026-09-07T01:00:00.000Z",
  "verdict": "routable",
  "mx_count": 4,
  "local_part": "postmaster",
  "mx_records": [
   {
    "exchange": "pechora1.icann.org",
    "preference": 10
   },
   {
    "exchange": "pechora6.icann.org",
    "preference": 10
   },
   {
    "exchange": "pechora7.icann.org",
    "preference": 10
   },
   {
    "exchange": "pechora8.icann.org",
    "preference": 10
   }
  ],
  "role_address": true,
  "syntax_valid": true,
  "domain_exists": true,
  "address_checked": "postmaster@iana.org",
  "free_mail_domain": false,
  "disposable_domain": false,
  "a_or_aaaa_fallback": false,
  "deliverable_domain": true,
  "checks_not_performed": [
   "no SMTP connection was opened",
   "mailbox existence was not tested and is not claimed",
   "no personal data was stored"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/spf-and-dmarc-record-checker-with-email-deliverability-validation-1236d82d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ai.rjhsignaltech.workers.dev](https://www.zero.xyz/host/ai.rjhsignaltech.workers.dev/llms.txt)